Recently, there is suggested a method in which a substrate such as a semiconductor wafer is subjected to liquid processing, and then the substrate after being processed with the liquid is dried by using a sublimable substance, and an example thereof is disclosed in JP 2012-243869 A.
In the method disclosed in JP 2012-243869 A, when drying the substrate by removing a liquid on the substrate having a concavo-convex pattern formed on a surface of the substrate, first, a sublimable substance solution is supplied to the substrate to fill a concave portion of the concavo-convex pattern of the substrate with the sublimable substance solution. Then, a solvent in the sublimable substance solution is dried to fill the concave portion of the concavo-convex pattern of the substrate with the sublimable substance in a solid state. Subsequently, the substrate is heated at a temperature higher than a sublimation temperature of the sublimable substance to remove the sublimable substance from the substrate. According to the method disclosed in JP 2012-243869 A, since the concave portion of the concavo-convex pattern of the substrate is filled with the sublimable substance in a solid state, and then the sublimable substance is sublimated to be removed from the inside of the concave portion, a stress caused by a surface tension of a liquid that exists on the substrate does not operate to the convex portion of the concavo-convex pattern of the substrate. Accordingly, it is possible to prevent falling-down of the convex portion, that is, collapse of the concavo-convex pattern.
Paragraph [0030] of JP 2012-243869 A discloses that when heating the substrate at a temperature higher than the sublimation temperature of the sublimable substance to remove the sublimable substance from the substrate, the substrate is heated at a temperature of 100° C. to 300° C.